let province=[
	["name","江苏"],
	["cities",["苏州","无锡","常州"]]
];
let p=Object.fromEntries(province)
console.log(p)
let str="    I Love You    ";
console.log(str.trimStart())
console.log(str.trimLeft())
console.log(str.trimEnd())
console.log(str.trimRight())
let arr=[1,2,3,4,[1,2,3,4,[1,2,3,4,[1,2,3,4]]]];
console.log(arr.flat())
console.log(arr.flat(2))
console.log(arr.flat(3))
const arr2=[1,2,3,4];
const result=arr2.flatMap(item=>[item*10]);
console.log(result)
